The Belarusian was thwarted by Russian Ekaterina Alexandrova 3-6, 6-3, 7-6 (7/5) in a tense encounter lasting over two and a half hours.

This was Sabalenka's first match since losing the Australian Open final in three sets to Madison Keys in January.

Alexandrova has turned up in Doha in good form after claiming her fifth WTA title in Linz last week.

The 26th-ranked Alexandrova picked herself up after going one set down to level in the second - but not before an unscheduled appearance by an inquisitive four-legged feline spectator.

With the score at 2-2, 40-30 to Sabalenka, a cat nonchalantly took centre stage, inspecting proceedings courtside before sauntering off via the player's entrance.

Alexandrova shrugged off the interruption to level the match, then held her nerve to force the deciding set to a tie-break which she took 7-5.

Sabalenka was back competing at the Qatar Open for the first time since 2022, having won the 2020 title in what is the first WTA 1000 event of the season.

Alexandrova's reward was a last-16 date with Belgian Elise Mertens.